I have to say ALL my kids are on PAYG ..... they get a monthly allowance of £10 each. If the THW want more she pays.

Wife and self also use PAYG. It is sooooooooooo much cheaper. Calls at 8p a min, texts cost 4p. ASDA PAYG mobiles for all. If you can't say what you need to say in a couple of minutes ~ write a letter or email.
The house phone calls (land line to land line) are free and I have two land lines. They are permitted to use one of them.
I also have Skype .... free Skype to Skype calls